No, I didn't want to record live but just thought the preview would be a quicker way to estimate the lighting quality. My plan was to do the keying later. So yes, I would have the ability to undo stuff if a client wanted.

When you mentioned On-Location, that was the kind of responses I was looking for - if a software like that can just give me a live preview. But I also wanted to hear things exactly like you said, like how you can also rely on the zebra and eyeball it - experienced feedback like that is very helpful to me.

I know that eventually, I will learn from trial and error but asking for help in forums like this one lets me educate myself a little more.